How Often Should You Flush an RO Membrane? Learn Here!

This page may contain affiliate links. If you buy a product or service through such a link we earn a commission at no extra cost to you. Learn more.

While not everyone flushes the membrane of their reverse osmosis system, some people do it to increase membrane lifespan.

How and how often should you flush an RO membrane?

Find out below!

Key Takeaways

  • You should ideally flush your RO membrane between once every few days and once a month – depending on the contamination level of your water supply.
  • Flushing is not strictly necessary as replacing the membrane is also a sensible option.
  • Watch out for signs that your membrane needs to be flushed, such as foul odors or tastes in the filtered water.

How Often Should You Flush an RO Membrane?

Recommendations about the ideal frequency of flushing an RO membrane vary across the board. Some claim that it should be done every day with no exceptions, while others flush their membranes once every one to four weeks.

In the end, what’s best for your RO membrane depends on various factors, including your water consumption levels and how contaminated your water supply is.

Also, as mentioned before, most people never flush their RO membranes and that’s fine. Under normal conditions, an RO membrane should still last 2-5 years.

Signs Indicating That Your Reverse Osmosis Membrane Is Due for a Flush

If you don’t want to orient yourself solely on time estimates and prefer to look out for signs that it’s time for flushing your RO membrane, there are several things you need to watch out for. These include:

  • Foul odors or tastes in the RO water
  • Drop in output water pressure
  • Salt permeability increasing by more than 10% – 15%

blue reverse osmosis membrane

How Do You Flush an RO Membrane?

Once you’ve decided that it’s time to flush your RO membrane, here’s how to do it:

  • Using a flush kit: Simply open the flush valve for 20-30 minutes.
  • Without a flush kit:
    1. Close the water supply to the system as well as the RO storage tank valve.
    2. Depressurize.
    3. Remove the flow restrictor from the drain line.
    4. Turn the water supply back on. Now the system is in flush mode.
    5. Wait for 20-30 minutes.
    6. Reinstall the flow restrictor.

RO Membrane Flushing Methods

The three main methods for flushing an RO membrane are forward flushing, backward flushing, and air water flushing. Forward flushing is the most straightforward and readily available for home use, but it can leave you with some contaminants that were not properly removed…

Forward Flushing

Forward flushing utilizes the feed side. It simply involves running water at a high pressure and volume, relying on the resulting turbulence to remove contaminants from the membrane. While this method is generally effective, it may be insufficient in some cases.

Backward Flushing

Backward flushing, on the other hand, uses the permeate side. Water is forced back through the system at a high pressure, which removes most contaminants from the membrane. Once again, pressure is the main force that removes foulants. Both forward and backward flushing can result in a lot of wasted water.

Air Water Flushing

Finally, with air water flushing, you use air bubbles on the feed side to cleanse the membrane. The extra turbulence created by the bubbles can help remove some of the more stubborn foulants, while the approach is relatively efficient in terms of water waste.

How to Give Your RO Membrane a Deep Cleanse

If you want to clean your RO membrane more thoroughly, you’ll need to disassemble the system and use cleaning chemicals. The process is not that complicated, but you must always take proper precautions and use protective wear.

  1. Prepare the chemical cleaning solution, following the manufacturer’s guidelines for the right concentration.
  2. Take out the RO membrane.
  3. Soak the RO membrane and give the chemicals enough time to work.
  4. Rinse the membrane as thoroughly as you can to remove any residue chemicals.
  5. Install the membrane back into the system and reassemble anything you’ve taken apart.
  6. Rinse one more time.

If you have any questions about how often to flush an RO membrane please don’t hesitate to leave a comment below!

About the Author Alexandra Uta

Alex is a content writer with an affinity for research and a methodical attention to detail. Since 2020, she has fully immersed herself into the home water treatment industry only to become an expert herself. Alex has been using water filters and similar products for years which has gained her lots of hands-on experience.
Learn more about .


Information provided on BOS is for educational purposes only. The products and services we review may not be right for your individual circumstances.
We adhere to strict editorial guidelines. Rest assured, the opinions expressed have not been provided, reviewed, or otherwise endorsed by our partners – they are unbiased, independent, and the author’s alone. Our licensed experts fact-check all content for accuracy. It is accurate as of the date posted and to the best of our knowledge.

Leave a Comment: